best 4* to 4/40 to complete act 4

stuck on 4.3.6 venom, trying to go through master mode, and magik is my only 4/40 champ so far. i only have respurces for one rank up, which 4* should i 4/40 which would help me at this stage in the game (not gonna do act 5 or rol anytime soon, just need a good champ to get through act 4 as im free to play)

Best champ out of the bunch for the long game would be Void or Midnight, not really wise to rank up a champ just to get past one guy. Think about what you want to play with out of the bunch and go with that champ.

i just need a champ to 4/40 at this current stage, when i get to longer fights i will definitely rank up proxima or void, but for completing act 4 (i just got to 4.4.2) and master mode in event quest which champ is better at this stage